Fermented milk is roughly classified into two types. One is a pre-fermentation type, obtained by fermenting raw material milk in a large-sized manufacturing tank, crushing the obtained fermented milk, and then packing the fermented milk in an individual food container. The other is a post-fermentation type, obtained by packing raw material milk, lactic acid bacteria, and the like in an individual food container and then fermenting the milk. In any type, the fermented milk packed and fermented in an individual food container is delivered to a final consumer on a distribution route.
Conventionally, on a distribution route, fermented milk in an individual food container may be broken disadvantageously, or in a case of fermented milk containing a fruit pulp, the fruit pulp may sink into a bottom of an individual food container disadvantageously. Examples of a method for preventing these problems include a method for adding a gelling agent such as agar or gelatin to fermented milk to increase the hardness of the fermented milk. However, by adding the gelling agent, fermented milk is hardly broken, but on the other hand, an original smooth texture of the fermented milk is lost disadvantageously.
In order to solve the above problem, a method for adding an enzyme in manufacturing fermented milk has been proposed (for example, see Patent Literatures 1 and 2). Patent Literature 1 discloses a method using peroxidase, and Patent Literature 2 discloses a method using transglutaminase.